Seven Natural Wonders of the United States

Arches National Park is famouse for the preservation of over 2,000 naturally occuring sandstone arches.  The highlight is the world famous Delicate Arch.  The highest elevation is 5,653 feet (1,723 m)

Crater Lake National Park is the fifth oldest national park in the United States.  Created from the caldera formed from the volcano Mount Mazama.  The lake is the deepest lake in the United States and the second deepest in North America.  It measures 1,943 feet (592 m) deep.

Hawaii Volcanoes National Park features two volcanoes that include Kilauea, which is considered the world's most active volcano, and Mauna Loa which is recognized as the largest subaerial volcano.  The park is identified as an International Biosphere Reserve and World Heritage Site.

Mount McKinley, also known as Denali, is the highest mountain peak in North America.  The peak reaches a summit of 20,237 feet (6,168 m).  The base to peak rise of Mount McKinley is considered the largest of any mountain situated entirely above sea level.

Old Faithful is a cone geyser within the boundaries of Yellowstone National Park.  It was the first geyser to receive a name, and it is considered one of the most predictable geographical features on hte planet.  It erupts almost every 91 minutes.

Niagara Falls is comprised of three falls that include Horseshoe Falls, American Falls, and the Bridal Veil Falls.  The combined falls account for the highest flow rate of any waterfall in the world.  The highest point of the falls is 167 feet (51 m).

Death Valley is the largest national park within the 48 states and is recognized as an International Biosphere Reserve.  It is the hottest and driest desert in the United States.  It is the second lowest point in the US at 282 feet (86 m) below sea level.

Rainbow Bridge National Monument is found in Glen Canyon NRA, Utah.  It is considered the world's highest natural bridge.  It expands 234 feet (71 m).  The center point is 42 feet (13 m) thick and 33 feet (10 m) wide.

The General Sherman is a giant seuoia tree found in Sequoia National Park, California.  It is recongized as the largest living single stem tree on earth.  It stands 275 feet (83.8 m) high and has a diameter of 25 feet (7.7 m).

The Coastal Redwoods and the Sequoias are both redwood trees and collectively represent the tallest and largest trees in the United States.  The tallest tree reaches 379.3 feet (115.6 m) high, whereas the largest sequoia tree is the General Sherman in Sequoia NP.  It has a diameter of 25 feet.

Devil's Tower is a laccolith in the Black Hills of Wyoming.  It measures 5,114 feet (1,559 m) high. It is a unique and iconic facet of nature repeated nowhere in the world.  The monument area encompasses 1,347 acres (545 ha).

Mammoth Cave is recognized as the longest cave system in the world.  It is both a World Heritage Site and an Internatioal Biosphere Reserve.  It has over 400 miles of surveyed passageways and is twice as long as the second longest cave system.

Yellowstone National Park has the distinction of being the first national park in the world.  It is famous for the geothermal features, variety of ecosystems and abundant wildlife.  It spans 3,468 square miles and is located over the Yellowstone Caldera, which is the largest supervolcano on the continent.